Mary, The Making Of A Princess will air on Ten in November and star Ryan O’Kane (as Prince Frederik) and Emma Hamilton (as Princess Mary). Photo: Ten Overshare…The Langham Hotel slipped a little peek of filming back in August. Photo: Instagram

It’s rare that actual royalty star in miniseries of their own lives but in Ten’s upcoming Mary: The Making of a Princess production, Crown Prince Frederik of Denmark will make a cameo appearance.

“When Emma [Hamilton, who plays Princess Mary] was filming some scenes in Copenhagen, there was a scene, that if you look really closely, you’ll see Prince Frederik. He drove past in his car while they had the cameras rolling,” the prince’s on screen alter ego Ryan O’Kane said.

O’Kane, who previously played cricketer Jeff Thomson in Howzat!, missed out on visiting the royal couple’s homeland and filming in Denmark but was equally impressed with the locations in Sydney.

“We were the first film crew allowed to shoot in Government House. We used the water fountains and halls for a few scenes. It was amazing, the paint work in there is awe inspiring,” the New Zealand native said.

Mary: The Making of a Princess was also shot on Sydney Harbour and inside the newly refurbished Langham Hotel.

Emotions ran high on set with many reduced to tears during certain takes.

“I’d look up after we’d break from some scenes and if the director was crying I’d knew we’d nailed it,” he said. “It was quite hard not to get too emotional in some circumstances.”

To prepare for the role as the unassuming future King of Denmark O’Kane worked with a dialect coach on set and “watched his wedding speech on YouTube like a hundred times. Not just trying to get the accent right but to mimic how he interacted with Mary and his family.”

The first look of the upcoming miniseries was released on Thursday and promises viewers “the story you don’t know” about the couple who met during the Sydney Olympics, married in May 2014 and now have four young children.

“It celebrates these two, celebrates their relationship. Trend spotters will no doubt have a field day saying ‘Oh you used the wrong tiara there’ but it’s a really positive story,” O’Kane said.

He confirmed the creators didn’t have a direct line to the palace or the couple’s friends, like Mary’s best n friend and maid of honour Amber Petty.

“The only connection to reality is the fact it was a real situation that unfolded, there was a lot of creative licence taken with the story.”

O’Kane is now preparing to start work on the upcoming Peter Brock miniseries.

“We just had our first read through. Growing up in New Zealand I have no real idea of who he was, so it is going to be a lot of fun learning more on set.”